Move definitions and methods related to QUIC versions, into quic_versions.{h,cc}. No behavior chang…

net/quic/core/quic_versions.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_QUIC_QUIC_VERSIONS_H_
+#define NET_QUIC_QUIC_VERSIONS_H_
+
+#include <string>
+#include <vector>
+
+#include "net/quic/core/quic_types.h"
+
+namespace net {
+
+// The available versions of QUIC. Guaranteed that the integer value of the enum
+// will match the version number.
+// When adding a new version to this enum you should add it to
+// kSupportedQuicVersions (if appropriate), and also add a new case to the
+// helper methods QuicVersionToQuicTag, QuicTagToQuicVersion, and
+// QuicVersionToString.
+enum QuicVersion {
+  // Special case to indicate unknown/unsupported QUIC version.
+  QUIC_VERSION_UNSUPPORTED = 0,
+
+  QUIC_VERSION_32 = 32,  // FEC related fields are removed from wire format.
+  QUIC_VERSION_33 = 33,  // Adds diversification nonces.
+  QUIC_VERSION_34 = 34,  // Deprecates entropy, removes private flag from packet
+                         // header, uses new ack and stop waiting wire format.
+  QUIC_VERSION_35 = 35,  // Allows endpoints to independently set stream limit.
+  QUIC_VERSION_36 = 36,  // Add support to force HOL blocking.
+
+  // IMPORTANT: if you are adding to this std::list, follow the instructions at
+  // http://sites/quic/adding-and-removing-versions
+};
+
+// This vector contains QUIC versions which we currently support.
+// This should be ordered such that the highest supported version is the first
+// element, with subsequent elements in descending order (versions can be
+// skipped as necessary).
+//
+// IMPORTANT: if you are adding to this list, follow the instructions at
+// http://sites/quic/adding-and-removing-versions
+static const QuicVersion kSupportedQuicVersions[] = {
+    QUIC_VERSION_36, QUIC_VERSION_35, QUIC_VERSION_34, QUIC_VERSION_33,
+    QUIC_VERSION_32};
+
+typedef std::vector<QuicVersion> QuicVersionVector;
+
+// Returns a vector of QUIC versions in kSupportedQuicVersions.
+NET_EXPORT_PRIVATE QuicVersionVector AllSupportedVersions();
+
+// Returns a vector of QUIC versions from kSupportedQuicVersions which exclude
+// any versions which are disabled by flags.
+NET_EXPORT_PRIVATE QuicVersionVector CurrentSupportedVersions();
+
+// Returns a vector of QUIC versions from |versions| which exclude any versions
+// which are disabled by flags.
+NET_EXPORT_PRIVATE QuicVersionVector
+FilterSupportedVersions(QuicVersionVector versions);
+
+// Returns QUIC version of |index| in result of |versions|. Returns
+// QUIC_VERSION_UNSUPPORTED if |index| is out of bounds.
+NET_EXPORT_PRIVATE QuicVersionVector
+VersionOfIndex(const QuicVersionVector& versions, int index);
+
+// QuicTag is written to and read from the wire, but we prefer to use
+// the more readable QuicVersion at other levels.
+// Helper function which translates from a QuicVersion to a QuicTag. Returns 0
+// if QuicVersion is unsupported.
+NET_EXPORT_PRIVATE QuicTag QuicVersionToQuicTag(const QuicVersion version);
+
+// Returns appropriate QuicVersion from a QuicTag.
+// Returns QUIC_VERSION_UNSUPPORTED if version_tag cannot be understood.
+NET_EXPORT_PRIVATE QuicVersion QuicTagToQuicVersion(const QuicTag version_tag);
+
+// Helper function which translates from a QuicVersion to a string.
+// Returns strings corresponding to enum names (e.g. QUIC_VERSION_6).
+NET_EXPORT_PRIVATE std::string QuicVersionToString(const QuicVersion version);
+
+// Returns comma separated list of string representations of QuicVersion enum
+// values in the supplied |versions| vector.
+NET_EXPORT_PRIVATE std::string QuicVersionVectorToString(
+    const QuicVersionVector& versions);
+
+}  // namespace net
+
+#endif  // NET_QUIC_QUIC_VERSIONS_H_